Growth and Differentiation Factor-8 (GDF8), also known as myostatin, is a member of the TGF-β superfamily of growth factors. GDF8 is a negative regulator of skeletal muscle mass, highly expressed in the developing and adult skeletal muscle.
GDF8 is highly conserved across species, and the amino acid sequences of murine and human GDF8 are identical (human GDF8 nucleic acid sequence and amino acid sequence shown in SEQ. ID NO:338-339) (McPherron et al. 1977 Nature, 387:83-90).
A number of human diseases are associated with loss or impairment of muscle tissue, for example, muscular dystrophy, muscle atrophy, muscle wasting syndrome, sarcopenia and cachexia, and inhibitors of GDF8 are applicable to treating these diseases or disorders.
Antibodies to GDF8 and therapeutic methods are disclosed in, e.g., U.S. Pat. No. 6,096,506, U.S. Pat. No. 7,320,789, U.S. Pat. No. 7,807,159, WO 2007/047112, WO 2005/094446, US 2007/0087000, U.S. Pat. No. 7,261,893, and WO 2010/070094.